32 research outputs found
Lowest-order QED radiative corrections in unpolarized elastic electron-deuteron scattering beyond the ultra-relativistic limit for the proposed deuteron charge radius measurement at Jefferson Laboratory
Analogous to the well-known proton charge radius puzzle, a similar puzzle
exists for the deuteron charge radius, . There are discrepancies
observed in the results of , measured from electron-deuteron ()
scattering experiments, as well as from atomic spectroscopy. In order to help
resolve the charge radius puzzle of the deuteron, the PRad collaboration at
Jefferson Lab has proposed an experiment for measuring , named DRad.
This experiment is designed to measure the unpolarized elastic scattering
cross section in a low- region. To extract the cross section with a high
precision, having reliable knowledge of QED radiative corrections is important.
In this paper, we present complete numerical calculations of the lowest-order
radiative corrections in scattering for the DRad kinematics. The
calculations have been performed within a covariant formalism and beyond the
ultra-relativistic approximation (). Besides, we present a
systematic uncertainty on arising from higher-order radiative
corrections, estimated based on our cross-section results.Comment: 16 pages and 6 figure
Elastic Positron-Proton Scattering at Low Q
Systematic differences in the the proton's charge radius, as determined by
ordinary atoms and muonic atoms, have caused a resurgence of interest in
elastic lepton scattering measurements. The proton's charge radius, defined as
the slope of the charge form factor at Q=0, does not depend on the probe.
Any difference in the apparent size of the proton, when determined from
ordinary versus muonic hydrogen, could point to new physics or need for the
higher order corrections. While recent measurements seem to now be in
agreement, there is to date no high precision elastic scattering data with both
electrons and positrons. A high precision proton radius measurement could be
performed in Hall B at Jefferson Lab with a positron beam and the calorimeter
based setup of the PRad experiment. This measurement could also be extended to
deuterons where a similar discrepancy has been observed between the muonic and
electronic determination of deuteron charge radius. A new, high precision
measurement with positrons, when viewed alongside electron scattering
measurements and the forthcoming MUSE muon scattering measurement, could help
provide new insights into the origins of the proton radius puzzle, and also
provide new experimental constraints on radiative correction calculations.Comment: 9 pages, 8 figures. arXiv admin note: substantial text overlap with
arXiv:2007.1508
The Solenoidal Large Intensity Device (SoLID) for JLab 12 GeV
The Solenoidal Large Intensity Device (SoLID) is a new experimental apparatus
planned for Hall A at the Thomas Jefferson National Accelerator Facility
(JLab). SoLID will combine large angular and momentum acceptance with the
capability to handle very high data rates at high luminosity. With a slate of
approved high-impact physics experiments, SoLID will push JLab to a new limit
at the QCD intensity frontier that will exploit the full potential of its 12
GeV electron beam. In this paper, we present an overview of the rich physics
program that can be realized with SoLID, which encompasses the tomography of
the nucleon in 3-D momentum space from Semi-Inclusive Deep Inelastic Scattering
(SIDIS), expanding the phase space in the search for new physics and novel
hadronic effects in parity-violating DIS (PVDIS), a precision measurement of
production at threshold that probes the gluon field and its
contribution to the proton mass, tomography of the nucleon in combined
coordinate and momentum space with deep exclusive reactions, and more. To meet
the challenging requirements, the design of SoLID described here takes full
advantage of recent progress in detector, data acquisition and computing
technologies. In addition, we outline potential experiments beyond the
currently approved program and discuss the physics that could be explored
should upgrades of CEBAF become a reality in the future.Comment: This white paper for the SoLID program at Jefferson Lab was prepared
in part as an input to the 2023 NSAC Long Range Planning exercise. To be
submitted to J. Phys.
Isolable and Well-Defined Butadienyl Organocopper(I) Aggregates: Facile Synthesis, Structural Characterization, and Reaction Chemistry
Four
types of alkenyl organocopperÂ(I) aggregates linked by 1,3-butadienyl
and/or 1,3,5,7-octatetraenyl moieties were selectively realized in
good isolated yields. All these organocopperÂ(I) aggregates were structurally
characterized by single-crystal X-ray structural analysis. These unprecedented
aggregates, stabilized by multiple Cu–Cu interactions and the
conjugated 1,3-butadienyl or 1,3,5,7-octatetraenyl bridges, could
undergo controlled structural transformations. The 1,4-dicopper 1,3-butadienyl
aggregate <b>3</b> could be efficiently transformed to aggregate <b>2</b>, while LiI could disaggregate the 1,3-butadienyl-1,3,5,7-octatetraenyl
aggregate <b>4</b> to 1,3,5,7-octatetraenyl aggregate <b>5</b> and 1,3-butadienyl aggregate <b>2</b>. Preliminary
reaction chemistry and synthetic applications of these organocopperÂ(I)
aggregates were also investigated
Isolable and Well-Defined Butadienyl Organocopper(I) Aggregates: Facile Synthesis, Structural Characterization, and Reaction Chemistry
Four
types of alkenyl organocopperÂ(I) aggregates linked by 1,3-butadienyl
and/or 1,3,5,7-octatetraenyl moieties were selectively realized in
good isolated yields. All these organocopperÂ(I) aggregates were structurally
characterized by single-crystal X-ray structural analysis. These unprecedented
aggregates, stabilized by multiple Cu–Cu interactions and the
conjugated 1,3-butadienyl or 1,3,5,7-octatetraenyl bridges, could
undergo controlled structural transformations. The 1,4-dicopper 1,3-butadienyl
aggregate <b>3</b> could be efficiently transformed to aggregate <b>2</b>, while LiI could disaggregate the 1,3-butadienyl-1,3,5,7-octatetraenyl
aggregate <b>4</b> to 1,3,5,7-octatetraenyl aggregate <b>5</b> and 1,3-butadienyl aggregate <b>2</b>. Preliminary
reaction chemistry and synthetic applications of these organocopperÂ(I)
aggregates were also investigated
Cyclopentadiene–Phosphine/Palladium-Catalyzed Cleavage of C–N Bonds in Secondary Amines: Synthesis of Pyrrole and Indole Derivatives from Secondary Amines and Alkenyl or Aryl Dibromides
An efficient Pd-catalyzed cleavage of CÂ(sp<sup>3</sup>)–N
bonds in secondary amines and a consequent CÂ(sp<sup>2</sup>)–N
and CÂ(sp<sup>3</sup>)–N coupling process was developed. Various
secondary amines could be used to react with alkenyl or aryl dibromides,
affording pyrroles and indoles in high yields. Cyclopentadiene–phosphine
ligands, a new type of P–olefin ligand, were found to be able
to promote the efficiency of this Pd-catalyzed process remarkably.
A reactive Pd complex coordinated with a cyclopentadiene–phosphine
ligand was successfully isolated and structurally characterized
Cyclopentadiene–Phosphine/Palladium-Catalyzed Cleavage of C–N Bonds in Secondary Amines: Synthesis of Pyrrole and Indole Derivatives from Secondary Amines and Alkenyl or Aryl Dibromides
An efficient Pd-catalyzed cleavage of CÂ(sp<sup>3</sup>)–N
bonds in secondary amines and a consequent CÂ(sp<sup>2</sup>)–N
and CÂ(sp<sup>3</sup>)–N coupling process was developed. Various
secondary amines could be used to react with alkenyl or aryl dibromides,
affording pyrroles and indoles in high yields. Cyclopentadiene–phosphine
ligands, a new type of P–olefin ligand, were found to be able
to promote the efficiency of this Pd-catalyzed process remarkably.
A reactive Pd complex coordinated with a cyclopentadiene–phosphine
ligand was successfully isolated and structurally characterized
Cyclopentadiene–Phosphine/Palladium-Catalyzed Cleavage of C–N Bonds in Secondary Amines: Synthesis of Pyrrole and Indole Derivatives from Secondary Amines and Alkenyl or Aryl Dibromides
An efficient Pd-catalyzed cleavage of CÂ(sp<sup>3</sup>)–N
bonds in secondary amines and a consequent CÂ(sp<sup>2</sup>)–N
and CÂ(sp<sup>3</sup>)–N coupling process was developed. Various
secondary amines could be used to react with alkenyl or aryl dibromides,
affording pyrroles and indoles in high yields. Cyclopentadiene–phosphine
ligands, a new type of P–olefin ligand, were found to be able
to promote the efficiency of this Pd-catalyzed process remarkably.
A reactive Pd complex coordinated with a cyclopentadiene–phosphine
ligand was successfully isolated and structurally characterized